1. Field of the Invention
This invention relates to propellants for a liquid propellant guns.
2. Description of the Prior Art
Considerable experimentation is now being carried on with liquid propellant guns. A liquid propellant gun is one in which a liquid propellant rather than conventional powder is utilized to provide the force which drives a projectile from the gun barrel. In a typical experimental liquid propellant gun, two liquid components, an oxidizer and a fuel, are injected into a chamber behind a projectile and sparked whereupon they burn, and produce gases which drive the projectile out of the barrel.
The liquid components must be of a nature such that they do not spontaneously ignite even when mixed in a very hot chamber. Quite obviously one would not wish to have a liquid propellant gun, or any other gun for that matter, fire spontaneously upon insertion of the propellant. Since many or perhaps most possible combinations of liquid oxidizer and fuel components tend to ignite spontaneously when mixed in a hot chamber, not many such combinations have become candidates for use as propellants for liquid propellant guns. In the past, n-octane and red fuming nitric acid (and other nitric acid concentrations) have been experimented with, with some success. This combination has drawbacks in that n-octane is expensive and the ballistic reproducability of the mixture leaves something to be desired. Also, combinations of TH-Dimer and nitric acid have been experimented with. These combinations have a drawback in that the TH-Dimer is a complex mixture of isomers which vary from batch to batch. Certain isomers are excessively reactive with nitric acid and this leads to "cook-off" problems. The ballistic reproducability of this combination also leaves something to be desired. Exo-tetrahydrodicyclopentadiene and nitric acid have also been experimented with and have yielded excellent results. However, the flash point of the exo compound is only about 132.degree. F. and this is lower than the 140.degree. F. specified for Navy shipboard applications. Also, the exo compound is not currently a commercially available material.